Valve-gear.



T. HALL -VALVE GEAR.

APPLICATION FILED MARL21, 1910.

979,002, Patented Dec. 20, 1910.

3 SHEETS-SHEET 1.

. Witnesses: Inventor 7n. 5. fiwzm. Attorney n: mamas pzrzns ca,wAsHmawN, a. 1;

T. HALL.

VALVE GEAR. APPLICATION FILLED 14111.21, 1910.

Patented Dec. 20, 1910.

3 SHEETS-SHEET 2.

Inventor w v S Attorney T. HALL.

VALVE GEAR.

APPLICATION rIL sD MAB..21, 1910.

979,002. Patented Dec.20,1910.v

BEHEETB-BEEBT 3.

ii 7 .w I

I :flfilllllHll: I v 5 Witnesses: Inventor m. S. fdm. Attorney UNITESTATES PATENT OFFICE.

THOMAS HALL, OF RIDGWAY, PENNSYLVANIA, ASSIGNOR T0 RIDGWAY DYNAMO &

ENGINE COMPANY, OF RIDG-WAY, PENNSYLVANIA.

' VALVE-GEAR.

Specification of Letters Patent.

Patented Dec. 20, 1910.

Application filed March 21, 1910. Serial No. 550,605.

To all whom it may concern:

Be it known that I, THOMAS HALL, a subject of the King of Great Britain,residing at Ridgway, Elk county, Pennsylvania, have invented certain newand useful Improvements in Valve-Gears, of which the in the class underconsideration the steam valves are always positively connected withtheir operating devices through mechanism designed to simulate, to agreater or less extent, the action of the Corliss gear in producingquick opening and quick closing of the steam-valves with long dwellsbetween the opening and the closing motion. These engines with theirsteam valves thus positively connected are generally. known asfour-valve engines.

The present invention relates to improvements in the valve-gear offour-valve engines and the improvements are designed to secure a closeapproach to the results of valve gears of the releasing type, and toprovide for the smooth working and durability of parts under verypeculiar conditions of sudden action and suddenly applied strains, andto lessen the number of parts.

The present invention will be readily understood from the followingdescription taken in connection with the accompanying drawingsdisclosing a preferred embodiment of the invention, in which drawingsFigure l is a diagram of the valve-gear in mid-position of main rocker:Fig. 2 a side elevation of the cylinder-end of an en-' gine fitted withthe gear: Fig. 3 a plan of the gear, minus the exhaust-valve mechanismand minus the cover of the rockerbox. Fig. 4- an elevation of the rockermechanism when the main rocker is at the extreme left position, the mainrock-shaft appearing in vertical section in the plane of line a of Figs.3, 7 and 8: Fig. 5 a similar view of the main rocker in mid-position,parts appearing in vertical section in the planes of lines a and b ofFig. 8: Fig. 6 a view similar to Fig. 4 but showing the main rocker inits extreme right position: Fig. 7

a plan of the rocker-box with its lid and upper portion removed: andFig. 8 a vertical section of the rocker-box in the plane of line cofFigs. 2, 3 and 7.

In the drawings :1, indicates the engine= frame: 2, the cylinder: 3, ahead-end steamvalve: 4, the crank-end steam-valve: 5, the head-endexhaust-valve: 6, the crank-end exhaust-valve: 7 an arm on eachvalve-stem: 8, an exhaust rock-shaft supported by the engine frameintermediate the cylinder and crank end of the frame: 9, a three-armedrocker on the exhaust rock-shaft; which rock-shaft may be a rock-shaftin fact or a fixed shaft for the rocker 9: 10, the exhaust eccentric-rodconnected with rocker 9: 11, exhaust-valve link connecting rocker 9 withthe arm of head-end exhaust-valve 5: 12, similar link connecting rocker9 with the arm of crank-end exhaust-valve 6, the links 11 and 12projecting from the exhaust rocker toward the cylinder: 13, a mainrockshaft supported by the bed forward of the exhaust rock-shaft: 14, adriving arm fast on this main rock-shaft: 15, the steam eocentric-rodconnected to driving arm 14: 16, a two-armed main rocker fast on mainrockshaft 13: 17, a pair of secondary rock-shafts supported by theengine-frame parallel with the main rock-shaft: 18, an arm fast on orformed with the outer end of each of the secondary rock-shafts: 19, asteam valve link connecting the arm of crank-end steam-valve 4 with thatone of the arms 18 which is farthest from the valve: 20, a similar butlonger steam valve link connecting the other arm 18 with the arm ofhead-end steamvalve 3: 21, an arm fast on or formed with each secondaryrock-shaft: 22, links connecting arms 21 each with an arm of main rocker16: 23, an open-topped rocker-box secured against the engine frame andfurnishing the bearings for the rock-shafts and inclosing the mainrocker 16 and arms 21 and links 22: 24, an upper portion of the rockerbox, joining the lower portion of the box in the plane of the axes ofthe secondary rock shafts: 25, a cover over the upper portion of therocker-box: 26, an outward projection from the outer wall of therockerbox to furnish bearings for exhaust rockshaft 8.

Referring to Figs. 4, 5 and 6, and before analyzing the motions oftheparts, it may be stated that the motions are such that very considerablestrains are brought rather suddenly upon certain of the parts and theconstruction is such as to best provide against evil effects from thesestrains. The arms of main rocker 16 and also the arms 21 are each madedouble so as to straddle the links 22 and each rock-shaft 17 is formedin one piece with its arm 21, arms 18 being also preferably formedintegral with their rock-shafts, the dividing of the rocker-boxproviding for the placing of the secondary rock shafts in theirbearings. The inclosure of the main rocker and its directly connectedmechanism within the rocker-box provides for bath or splash lubrication,and the removal of the cover of the rocker-box gives access to all ofthe parts within the box.

Diagrannnatic Fig. 1 shows the parts with the rockers in mid-positioncorresponding with Figs. 2 and Vhile main rocker 16 moves from themid-position shown inFig.

tothat shown in Fig. 1- the right-hand one of arms 18 will be withoutfunctional effectuponthe head steam-valve 1, which valve will dwell inclosed position. At the same time the left-hand one of arms 18 will haverocked through nearly a quarter of a circle thus widely and quicklyopening head-end steam-valve 3. hen the main rocker moves from themid-position of Fig. 5 to the rightward position of Fig. 6, the lefthandone of arms 18 will be practically idle while the right-hand one of arms18 will have quickly swept through its quarter circle. The exhaust-valves are actuated in an obvious manner through their rocker 9independentof the steam valves.

The mechanism at the rocker-box not only serves in bringing about thehighly important peculiar movements of the steam valves, as has beenexplained, but itserves also as a substitute for the usual specialrockers mounted upon engine frames between the cylinder and crank-end ofthe frame to shorten the eccentric rods, it thus becoming practicable toemploy short eccentric rods and desirably connecting therocker-mechanism with the valve arms.

Looking at Fig. 1, showing the rocker system in mid-position, it is tobe observed that steam valve-rods 19 and 20 are substantially in linewith arms 18 or, in other words, they are substantially in lines cuttingthe axes 17 and the pivots uniting them to the arms 18. In this positionthere may be considerable rocking motion of the arms 18 without anymaterial effect on the steam valves and whatever motion effect there maybe on the steam valves is transmitted with considerable power. Thoseskilled in the art understand that the valves are at certain timessubstantially balanced and at other times unbalanced. In the presentconstruction of valve gear it will be found, upon analysis, that themoving power becomes applied most advantageously to the valves when theyare in unbalanced condition and hardest to move.

The relationship between arms 16 and their links 22 and their arms 21 isseen to be such as to cause a dwell of the crank-end steanrvalve whenthe parts are at or near the position shown in Fig. 5. This togetherwith the relationship between arms 18 and their respective valve-links19 and 20 cause an unusual and very desirable period of dwell during theunbalanced period, and at the same time provides for rapid movements ofthe steam-valves.

I claim 1. Four-valve engine valve-gear comprising, a main rocker, arodconnection thereto for oscillating it, a pair of secondary rockersnear the main rocker, a pivot carried by each secondary rocker, a linkconnecting each of said pivots with the main rocker, an additional pivotcarried by each secondary rocker, and a link connecting each of thelast-mentioned pivots with one of the steam valves, combinedsubstantially as set forth.

2. Four-valve engine valve-gear comprising, one main rocker supported bythe engine f ame between the cylinder and crank end, a rod-connectionthereto for oscillating it, a pair of secondary rockers located onopposite sides of the center of the main rocker, a pivot carried by-eachsecondary rocker, a link connecting each of said pivots with the mainrocker, an additional pivot carried by each secondary rocker, and a linkconnecting each of the last-mentioned pivots with one of the steamvalves, combined substantially as set forth.

3. Four-valve engine valve-gear comprising, a main rocker, arod-connection thereto for oscillating it, a pair of secondary rockersnear the main rocker, pivot carried by each secondary rocker, a linkconnecting each of said pivots with the main rocker, an additional pivotcarried by each secondary rocker, a link connecting each of thelast-mentioned pivots with one of the steam valves, an exhaust rockermounted near the main rocker, a rod-connection to the exhaust rocker foroscillating it, a pair of pivots carried by the exhaust-rocker, and alink connecting each of the last-mentioned pivots with one of theexhaust-valves, combined substantially as set forth.

4. Four-valve engine valve-gear comprising, a fixedly supportedrocker-box, a main rock-shaft ournaled in said box, an arm on the outerend of said shaft, a rod-connection to said arm for oscillating the rockshaft, a main rocker 011 the rock-shaft within said box, a pair ofsecondary rock-shafts journaled in said box, an arm on each sec ondaryrock-shaft within said box, a link connecting each of the last-mentionedarms with the main rocker, an arm on the outer end of each secondaryrock-shaft, and a link connecting each of said last-mentioned arms withone of the steam valves, combined substantially as set forth.

Four-valve engine valve-gear comprising, a fixedly supported rocker-box,a main rock-shaft journaled in said box, an arm on the outer end of saidshaft, a rod-connection to said arm for oscillating the rock-shaft, amain rocker on the rock-shaft within said box, a pair of secondaryrock-shafts journaled in said box, an arm on each secondary rock-shaftwithin said box, a link connecting each of the last-mentioned arms withthe main rocker, an arm on the outer end of each secondary rock-shaft, alink connecting each of said last-mentioned arms with one of the steamvalves, an outward projection from the box at the bearing of the mainrockshaft, an exhaust rock-shaft journaled in said box and projection,an exhaust rocker on said rock-shaft, a rod-connection to said exhaustrocker for oscillating it, a pair of pivots carried by theexhaust-rocker, and a link connecting each of said lastmentioned pivotswith one of the exhaust-valves, combined substantially as set forth.

(3. Four-valve engine valve-gear comprising, a fixedly supportedrocker-box, a separable upper portion of said box, a main rockshaftjournaled in said box, an arm on the outer end of said shaft, arod-connection to said arm for oscillating the rock-shaft, a main rockeron the rock-shaft Within said box, a pair of secondary rock-shaftsjournaled in said box in the plane of separation between the main andupper portions of the box, an arm on each secondary rock-shaft withinsaid box, a link connecting each of the last-mentioned arms with themain rocker, an arm on the outer end of each secondary rock-shaft, and alink connecting each of said last-mentioned arms with one of the steamvalves, combined substantially as set forth.

7 Four-valve engine valve-gear comprising, a fixedly supportedrocker-box," a main rock-shaft journaled in said box, an arm on theouter end of said shaft, a rod-connection to said-arm for oscillatingthe rock-shaft, a main rocker on the rock-shaft within said box andprovided with bifurcated pivotarms, a pair of secondary rock-shaftsjournaled in said box, a bifurcated arm on each secondary rock-shaftwithin said box, a link connecting each of the last-mentioned arms withthe main rocker and disposed within the bifurcations of the arms, an armon the outer end of each secondary rock-shaft, and

av link connecting each of said last-mentioned arms with one of thesteam valves, combined substantially as set fort-h.

8. Four-valve engine valve-gear comprising, a main rocker, arod-connection thereto for oscillating it, a pair of secondary rockersnear the main rocker, a pivot carried by each secondary rocker,valve-connections to the secondary rockers, and links connecting saidpivots with the main rocker, the relationship of rocker-centers andpivot-centers being such that when the main rocker is in mid-positionthe main rocker and the two pivots of a link will be substantially in acommon plane, combined substantially as set forth.

9. Four-valve engine valve-gear comprising, a main rocker, arod-connection thereto for oscillating it, a pair of secondary rockersnear the main rocker, a pivot carried by each secondary rocker,valve-connections to the secondary pivoted rockers, and links connecting said pivots with the main rocker, the relationship ofrocker-centers and pivotcenters and valve connections being such thatwhen the main rocker is in mid-position the main rocker and the twopivots of a link will be substantially in a common plane and at the sametime the center of each secondary rocker will lie in substantially thesame plane as its valve-connection and the pivot connecting its valveconnection with it, combined substantially as set forth.

10. Four-valve engine valve-gear comprising a rocker-box, a main rockerjournaled therein, connection to said rocker for oscillating the same, apair of secondary rockers journaled in the rocker-box, a pivot carriedby each secondary rocker, links connecting said pivotswith the mainrocker, and valve connections to the secondary rockers.

11. Four-valve engine valve-gear comprising a rocker-box, a main rockerjournaled' therein, connection to said main rocker for oscillating thesame, a pair of secondary rockers journaled in the rocker-box, a pivotcarried by each secondary rocker, links connecting said pivots with themain rocker, steam valve connections to the secondary rockers, anexhaust rocker journaled on the rocker-box, connection to said exhaustrocker for oscillating the same, a pair of pivots carried by the exhaustIOCkBIQfiHd a link connecting each of the last-mentioned pivots with oneof the exhaust valves.

- THOMAS HALL.

Witnesses HARRY A. GAYLoR,

CARL A. FAY.

